A variety of automated chemical product dispensing systems that dispense chemical products are in use today. These chemical products come in a variety of forms, including, for example, fluids, solid product concentrates, powders, pellets, gels, extruded solids, etc. Automated chemical product dispensers are useful in many different chemical application systems, including cleaning systems relating to laundry operations, warewashing operations (e.g., a dishwasher), water treatment operations, and pool and spa maintenance, as well as other systems, such as food and beverage operations and agricultural operations. For example, chemical products used in a warewashing operation may include detergent, de-ionized water, sanitizers, stain removers, etc. Chemistry used in agriculture may include without limitation pesticides, herbicides, hydration agents and fertilizers. Other applications of the present invention may be used in, without limitation, dairies and dairy farms, (e.g., in teat dips); breweries; packing plants; pools spas, and other recreational water facilities; water treatment facilities, and cruise lines. Other chemical products may include without limitation glass cleaning chemicals, hard surface cleaners, antimicrobials, germicides, lubricants, water treatment chemicals, rust inhibitors, etc.
In some dispensing applications, it is desirable to know how much of the product has been dispensed. One type of system which measures how much of a chemical product has been dispensed determines the dispensed amount of chemical product based on mass. In one such system, a chemical product is dispensed by spraying a solid block of the chemical product with a diluent. A resultant use solution is created through erosion and dissolving of the chemical product via the diluent. A weight measurement instrument, such as one or more load cells, measure the weight of the chemical product remaining in the dispenser at various times throughout the dispensing cycle. The dispenser includes a controller that determines a change in weight of the chemical product remaining in the dispenser and thus determines the amount (or weight) of chemical product dispensed. Examples of such mass-based dispensing systems are described in U.S. Pat. No. 7,201,290 to Mehus et al., issued Apr. 10, 2007, U.S. Pat. No. 7,410,623 to Mehus et al., issued Aug. 12, 2008, and U.S. patent application Ser. No. 10/436,454, filed May 12, 2003, each of which is incorporated herein by reference in their entirety.